OK, after much tweaking, testing and rewriting I finally have something that I show off here for some testing. Take a look at the current version of LB-Radio here:
https://datasets.listenbrainz.org/lb-radio
Documentation on how to use this:
https://troi.readthedocs.io/en/lb-radio/lb_radio.html
Stealing two examples from the docs:
artist:(pretty lights):3:easy tag:(trip hop):2 artist:morcheeba:1:nosim
This prompt will play 3 parts from artist “Pretty Lights”, 2 parts from the tag “trip hop” and 1 part from the artist “Morcheeba” with no tracks from similar artists.
tag:(deep house):2:medium tag:(metal):1:hard artist:blümchen:2:easy
This will play 2 parts from tag “deep house” on medium mode, 1 part from tag “metal” on hard mode and 2 parts from artists “Blümchen” on easy mode. And serve for a fair amount of ipod whiplash. 
Please take a look and see if you find any bugs or clear improvements that ought to be made. Please keep in mind that this is far from ready to go into production and it intended for community testing. We’ll create a much nicer interface for this later, but right now this is what we’re using to test the underlying tech we’ve created. (without AI, at that!)
Questions, comments? Post them here for the time being. Happy playing!